Explosive disconnect



Oct. 16, 1962 R. H. BAIRD EXPLOSIVE DISCONNECT Filed Nov. 21, 1960 3Sheets-Sheet l INVENTOR. RICHARD H. BAIRD Z Kgnt Oct. 16, 1962 R. H.BAIRD EXPLOSIVE DISCONNECT 3 Sheets-Sheet 2 Filed Nov. 21, 1960INVENTOR. RICHARD H. BAIRD Oct. 16, 1962 R. H. BAIRD 3,059,207

EXPLOSIVE DISCONNECT Filed Nov. 21, 1960 s Sheets-Sheet 3 J sn i E'RICHARD H. g z x' l Agent rates tent 3,59,2d7. Patented Oct. 16, 19623,059,207 EXPLGSIVE DISCUNNEQT Richard H. Baird, Santa Cruz, Calif.,assignor to Loci;- heed Aircraft Corporation, Burbank, Calif. Filed Nov.21, 1960, fier. No. 70,632 8 Claims. (til. 339-45) This inventionrelates to pyrotechnic devices and is more particularly directed to anexplosively actuated disconnect assembly.

The use of explosive power to perform various mechanical functions iswell known, and many devices have heretofore been proposed utilizingthis motive force to initiated their functioning. A few of these deviceshave been directed to the function of disconnecting electrical linesbetween different stages of missiles and the like, and their utility hasbeen emphasized by the fact that they may be remotely operated with aminimum electrical impulse from a great distance. One of the devices ofthe prior art with which applicant is familiar has been linearlyactuated by an explosive charge placed between the two components to beseparated, and there has been no provision made for a closed systemcontainment of the actuating gases produced from the explosion. Thesegases, of course, have an adverse chemical effect upon the surroundingstructure in addition to contaminating the atmosphere in the vicinity ofthe explosion. Other devices have proven to be extremely violent intheir reaction, often causing physical damage to delicate parts mountednear the disconnect assembly.

It is thus an object of the present invention to provide an explosivelyactuated disconnect mechanism which will non-violently cause aseparation of a plug and receptacle to which it is connected.

Another object of the present invention is to provide such a device inwhich the high pressure gases generated from the actuating explosion arecompletely contained within the actuating mechanism thus preventingphysical and chemical damage to surrounding parts.

An additional object is to provide an explosive disconnect assemblywhich is adaptable to providing disconnect function to a wide variety ofconnectors both for electrical, gaseous, and hydraulic lines, which isextremely reliable, which meets strict Government requirements, andwhich is relatively easy to fabricate.

Additionally, an object of the invention is to provide an explosivelyactuated disconnect mechanism which may be refunctioned a number oftimes without special part replacement other than the explosive cells.

A still further object of the invention is to provide a device of thetype described which is quite insensitive to high and low temperatureextremes, violent vibration, rapid acceleration, humidity and chemicalcorrosion.

With these and other objects in mind the invention will be moreparticularly described in connection with the accompanying drawingswherein FIGURE 1 is a view in perspective showing the various componentsof the invention in an exploded relation,

FIGURE 2 is an end elevational view of the invention,

FIGURE 3 is a view shown partly in section taken along line 3--3 ofFIGURE 2,

FIGURE 4 is an end elevational view of the body assembly of theinvention, and

FIGURE 5 is a view shown partly in section taken along lines 5-5 ofFIGURE 4.

Referring first to FIGURE 1, the invention is shown in a fragmentary orexploded relation by which the interrelation of the parts is more easilyexplained. The numeral 1 indicates generally the overall assembly whilenumeral 2 denotes the stationary assembly such as is adapted to bepermanently aflixed to the structural frame of a vehicle, chassis, orthe like. Reference numeral '3 designates the disengageable assemblywhich is adapted to be disconnected from assembly 2.

Referring to stationary assembly 2, it will be seen that a bulkhead 10is provided with a plurality of apertures 11 which are adapted toreceive screws 1-2 interrelating with nuts 13 to securely fasten areceptacle 14' thereto. It is noted that bulkhead 1d may refer to anystructural assembly such as a bulkhead or outer skin of a missile or thelike or to any basic frame structure to which a disconnect assemblymight be engaged. Receptacle 14 is shown to be an electrical assemblysuch as may be composed of a cylindrical housing 15 containing aplurality of electrical connector pins 16 and which is provided with amounting flange 17 containing a series of apertures 23 to receive bolts12. On the other side of bulkhead 10 are a plurality of electrical wires18 forming an electrical cable,

,which wires are connected as desired to the pins 16. As

shown, a potting boot 19 surrounds the portion of the wires as theyenter into cylindrical housing 15, which potting boot is adapted to besecured to a potting boot retainer ring 20 in a manner known in the art.Potting boot retainer ring 26 is desirably threadably attached to aportion of the cylindrical housing 15, and the potting boot 19 is filledor potted with a suitably chosen dielectric compound of conventionallyavailable type. It should be noted that the inner surface of cylindricalhousing 15 is provided with a series of spline grooves 21 which areadapted to mate with spline tabs on a plug portion which will bedescribed hereinbelow. Also provided upon the outer peripheral surfaceof cylindrical housing 15 are a number of cam stubs 22 which serve animportant function to be described hereinafter.

A feature of the invention resides in the attachment of a base plate 30,formed of a lightweight material of substantial strength such as heattreated alloy steel, to bulkhead 10 which is desirably accomplished byproviding a number of apertures 31 which register with apertures 11 inbase plate 10. It will be seen that base plate 30 is centrally,preferably coaxially provided with a large aperture 32, which is adaptedto receive one end of cylindrical housing 15 therewithin. A number ofcam stub slots 33 are provided around the periphery of center aperture32 which register with cam stubs 22 on cylindrical housing 15 as thehousing is inserted into the center aperture 32. Important to note isthe fact that base plate 30 is provided with a pair of turned up backingflanges 34 which are preferably formed at right angles to the backingportion of base plate 30, these backing flanges being on opposite sidesof the base plate member.

Referring now to the disengageable assembly 3, it will be seen that aplug 40, preferably cylindrical in shape, is shown which is composed ofa cylindrical body portion 4 1 having an outside shoulder 12 about thecentral periphery thereof. A series of spline tabs 43 are provided whichare generally parallel to the axis of the plug member. The other end ofcylindrical body portion 41 is preferably provided with a threadedsurface 44'.

Adapted to cooperate with the base plate 3G in a manner which will bemore particularly described hereinbelow is a body assembly &9 which iscomprised of a body member 50 shown to be generally rectangular in shapeand which is provided with a centrally located passageway 51 extendingtherethrough. It is important to note that the peripheral walls 52 ofpassageway 51 are provided with at least one and preferably three spiralcamming grooves 53 which gently descend from and open upon the surfaceof body assembly 49 next adjacent plug 40. Desirably, these spiralcamming grooves 53 extend over approximately 'a ninety degree arcuateportion of the peripheral walls 52 of passageway 51.

As best seen in connection With FIGURES 2 and 3, body member 50 isprovided with at least one pair of interconnected shafts, one shaft ofeach pair being a squib shaft as at 54 and the other, a piston shaft asat 55, preferably formed at right angles to squib shaft 54, andinterconnected thereto through aperture 56. It should be noted thatsquib shaft 5 4 does not extend completely through body member 50 butstops considerably short of the opposite surface from which it opens toinsure that the wall between the bottom of the shaft and the other sideof body member 50 is structurally substantial. It is noted that bodymember 51) is formed preferably of a lightweight metal such as aluminum,magnesium, or the like.

Piston shaft 55 opens upon a side surface such as 58 of body member 50and is provided with an enlarged portion 59 about the periphery thereof.A piston 65 is slidably journaled within piston shaft 55', it beingnoted that piston 65 is provided at one end thereof with a pair ofspaced radial flanges 66 which form a groove therebetween which isadapted to receive an O-ring 67. The diameter of each radial flange 66is just slightly less than the internal diameter of the piston shaft 55,thus furnishing a guiding surface to insure a smooth sliding fit at thatend of the piston. The opposite end of piston 65 is preferably roundedand is adapted to be received within a piston guide bearing 68 which isinserted into the enlarged portion 59 of piston shaft 55. It is notedthat this piston guide bearing is preferably of metallic material whichmay contain a self lubricated bearing surface as desired. Threadablyreceived within squib shaft 54 is a squib 70 containing an explosivecharge which may be electrically initiated. Squibs of the type bestsuited for use in connection with the invention are commerciallyavailable, it having been found that M79 Mod. VIII or M130 Mod. Iavailable from McCormick iSelph Associates (Hollister, California) areparticularly suitable. A similar structure is provided at the oppositeend of body member 50, including a squib shaft 54-, piston shaft 55,containing a squib and piston assembly respectively as describedimmediately above. The squib assemblies are sealed into engagement withthe body member 5t} through 0-rings '71.

In addition to spiral camming grooves 53- formed Within peripheral wall52, an inwardly extending shoulder 74- is provided next adjacent theouter surface 75 of body member 50. In fabricating the disengageableassembly 3, plug 40 is inserted into the aperture in body member 50 sothat flange 42 engages with shoulder 74-, preventing the plug 40 frompassing completely through the body member 50. Plug 4t} is retained inthis position by means of a potting boot retaining ring 8 1 which isadapted to be threadably engaged with threads 44 on plug 40. Desirably,a radial, annular spring washer 8th is provided between flange 42 andshoulder 74 to insure that a positive electrical contact is maintainedbetween the plug 40 and receptacle 14. This spring washer St} isinserted over threads 44 on the cylindrical body portion 41 of plug 40and assures that potting boot retaining ring 81 is not tightened downupon the threads to such an extent that plug 40 is not freely rotatableas it is thus secured within body member 50. As in connection withstationary assembly 2, a potting boot 82 of polytetrailuoroethylene orthe like is attached to the potting boot retaining ring 81, and apotting compound such as General Electric RTP-60 potting compound isimplaced around the wires 83 extending through the assembly forconnection with sockets (not shown) in plug 40.

Assembly and Operation In assembling the invention, the stationaryassembly 2 is fastened to a bulkhead in the manner indicated above bythe use of screws 12. Likewise, disengageable assembly 3 is assembled asdescribed immediately above, and the two assemblies are ready forinterengagement. To effect this interengagement, spline tabs 43 on plug40 are 4 p keyed into the spline grooves 21 in cylindrical housing 15,thus effecting electrical connection between the wires leading into plug40 and those wires 18 connected with pins 16. As plug 44} is insertedinto receptacle 14, care should be taken to assure that cam stubs 22register into spiral camming grooves 53 in body member 50, it beingnecessary to rotate body member 50 to effect a complete interengagementof the parts. A safety Wire is then connected and secured betweenbacking flanges 34 and body member 50, it being noted that other knownsafety arrangements could be provided. The explosive disconnectassembly, thus ready for operation, is actuated by an electrical impulsewhich initiates one or both of explosive squibs 70. Referring to FIGURE3, it will be apparent that the explosive gases generated will primarilyexpand into squib shaft 54 and thence through opening 56 into pistonshaft 55, forcing piston 65 to move outwardly of the body member 50. Inso doing, the end of piston 65, impinging upon backing flanges 34 willimpart a reactive rotary movement to the whole of body member 50. Asbody member 50 is rotated, safety wire 100 is broken and cam studs 22,riding within spiral camming grooves 53 force body assembly 49 includingplug 4t) outwardly. Manifestly, While both rotary and axial movement isimparted to body member 50, only an axial motion is imparted to plug 40because of its rotatable mounting within body member 50. The electricalconnection pins within receptacle 14 and the mating electrical contactsin plug 40 are not damaged.

It is noted that any propensity toward violent action or recoil of thissystem is conveniently damped out by spinning the body member 50 aboutthe connector while disengagement of the connector or plug 40 occurs.Many actual tests have shown that disengageable assembly 3 is thrownonly a few inches from stationary assembly 2 as the disconnection isaccomplished, it being noted that previously available devices haveviolently reacted causing the disconnected portion thereof to move asfar as twelve feet unless they are sooner stopped by interveningstructure. Additional dampening is obtained by the twisting of theelectrical harness.

Additionally, O-ring 67 in piston shaft 55 prevents escape of theexplosive gases through this shaft and as the squib cap remains sealed,the explosive gases are thus effectively contained within the system.

It is noted that the disconnect device I have disclosed will effectivelyoperate upon functioning one squib only, it being desirable, however, tofunction both squibs for the disconnect. A reliability approaching onehundred percent is thus provided. The unit has withstood severetemperature cycling, shock and vibration tests, and has remainedoperative from a low of 80 F. to a high of over 300 F. Similarly, ashock of 40 GS with a 2 millisecond rise time and 6 millisecond dwelltime has been applied to a test assembly in each direction along threemutually perpendicular axes, with no mechanical failures or malfunctionsbeing observed. Similar exhaustive testing has shown insensitivity toviolent acceleration, vibration, humidity, and the like.

Referring to FIGURES 4 and 5, a modification of the invention is shownwherein a body member is provided with an insert sleeve 151. In thismodification, sleeve 151 is provided with the desired spiral camminggrooves 153 and is additionally provided with inwardly extendingshoulder 174 which performs a function similar to shoulder 74 describedin connection with FIGURES 1 through 3.

While sleeve 151 may be inserted within body member 150 in a variety ofways, it has been found desirable to shrink fit the two memberstogether. In this procedure of assembly a wide temperature variation isprovided between sleeve 151 and body member 150 so that the two membersmay be interfitted and allowed to cool, thus producing an extremelytight shrink fit. Operation of the device incorporating the modificationdisclosed in FIG- URES 4 and 5 is precisely the same as described above.The annular spring washer in this instance is positioned between theshoulder 174 and flange 42.

It should be understood that while the device has been described inconnection with an explosive disconnect device for disconnectingelectrical wiring, the invention has equal utility in effectingseparation between lines carrying fluids and the like, the interactionbeing susbtantially the same if fluid line connectors were substituted,for example, for receptacle 14 and plug 40.

While certain preferred embodiments of the invention have beenspecifically disclosed, it is understood that the invention is notlimited thereto, as many variations will be readily apparent to thoseskilled in the art, and the invention is to be given the broadestinterpretation within the terms of the following claims.

What is claimed is;

1. A remotely actuable disconnect assembly comprising first and secondinterregistrable connectors, a body member rotatably secured around saidsecond connector, explosive actuating means connected to said bodymemher for effecting rotation thereof relative to said first conncctor,said actuating means including a base plate secured to said firstconnector, said base plate having at least one backing flangeoutstanding substantially normally therefrom, at least one pistonslidably mounted Within said body member at approximately a right angleto said backing flange, means for exerting pressure against said pistonwhereby said piston pressing against said backing flange causes arotation of said body assembly relative to said first connector, andcamming means connected to said body member for effecting a lineardisconnecting movement of said body member and said second connectorrelative to said first connector.

2. A remotely actuable disconnect assembly as claimed in claim 1 inwhich said means for exerting pressure against said piston is anelectrically actuated explosive squib, and in which the gases producedby the actuation of said squib are completely sealably contained withinsaid body member.

3. A remotely actuable disconnect assembly comprising aninterconnectable receptacle and plug, a base plate having at least onebacking flange outstanding substantially normally therefrom secured tosaid receptacle, a body member rotatably secured upon said plug, saidbody member being formed with a centrally located passageway extendingtherethrough, a plurality of annular spiral camming grooves formedwithin the walls of said passageway, a plurality of cam stubs radiallyextending from the outer surface of said receptacle registrable withsaid spiral camming grooves, at least one piston shaft located in saidbody member, a piston in said shaft contacting and extendingsubstantially normally to said backing flange When said plug is receivedin said receptacle, said body member being provided with a squib shafttherein extending inwardly from one surface thereof, and connecting withsaid piston shaft, and an electrically initiable explosive squib withinsaid squib shaft.

4. A remotely actuable disconnect assembly comprising aninterconnectable receptacle and plug, a base plate having at least onebacking flange outstanding substantially normally therefrom secured tosaid receptacle, a body member rotatably secured upon said plug, saidbody member being formed with a centrally located passageway extendingtherethrough, an intimately fitting sleeve lining at least a portion ofthe walls of said passageway, one end of said sleeve terminating in aninwardly extending annular flange and the other end thereof providedwith a plurality of annular spiral camming grooves formed in the wallsthereof, a plurality of cam stubs radially extending from the outersurface of said receptacle registrable with said spiral cam grooves, atleast one piston shaft located in said body member, a piston in saidshaft contacting and extending substantially normally to said backingflange when said plug is received in said receptacle, said body memberbeing provided with a squib shaft therein extending inwardly from onesurface thereof and connecting with said piston shaft, and anelectrically initiable explosive squib Within said squib shaft.

5. A remotely actuable disconnect assembly comprising first and secondlinearly interregistrable connectors, a pair of backing flangesconnected to said first connector and outstanding substantially normallytherefrom toward said second connector, a body member having apassageway extending therethrough, said second connector extendingthrough said passageway and rotatably secured to said body member,actuating means in said body member actuable against said backingflanges causing rotation of said body member relative to said backingflanges, the passageway in said body member being formed with aplurality of annular spiral camming grooves, a plurality of cam stubsoutstanding from the peripheral surface of said first connectorreceivable in said camming grooves, whereby as said body member isrotated said second connector is linearly disengaged from said firstconnector.

6. A remotely actuable disconnect assembly comprising first and secondlinearly interregistrable connectors, a pair of backing flangesconnected to said first connector and outstanding substatially normallytherefrom toward said second connector, a body member having apassageway extending therethrough, said second connector extendingthrough said passageway and rotatably secured to said body member,camming means connected to said body member for effecting a lineardisconnecting movement of said body member and said second connectorrelative to said first connector, said body member being formed with apair of piston shafts extending at substantially ninety degrees to saidbacking flanges, a piston slidably, sealably journaled in each of saidpiston shafts with the outer end thereof in contact with said backingflanges,

a pair of closed squib shafts extending from the surface of said bodymember into the interior thereof, a passageway connecting each of saidsquib shafts respectively with said piston shafts, explosiveelectrically-actuable squibs sealingly engaged within and closing thesurface opening of each of said squib shafts, whereby as said squibs areactuated, the explosive gases generated thereby remain sealed withinsaid body member, and said body member is rotated in relation to saidfirst connector.

7. A remotely actuable disconnect assembly comprising first and secondlinearly interregistrable connectors, a pair of backing flangesconnected to said first connector and outstanding substantially normallytherefrom toward said second connector, a body member having apassageway extending therethrough, said second connector extendingthrough said passageway and rotatably secured to said body member,actuating means in said body member for effecting rotation thereofrelative to said backing flanges, said passageway being formed with aplurality of annular spiral camming grooves, a plurality of cam stubsoutstanding from the peripheral surface of said first connectorreceivable in said camming grooves, said body member being formed with apair of piston shafts extending at substantially ninety degrees to saidbacking flanges, a piston slidably, sealably journaled in each of saidpiston shafts with the outer ends thereof, respectively, in contact withsaid backing flanges, a pair of squib shafts extending from the surfaceof said body member into the interior thereof, a passageway connectingeach of said squib shafts, respectively, with said piston shafts, anexplosive electrically-actuable squib sealingly engaged within andclosing the surface opening of each of said squib shafts, whereby, assaid squibs are actuated, the explosive gases generated thereby remainsealed within said body member, said body member being rotated inrelation to said first connector, said second connector being therebylinearly disengaged from said first connector.

8. A remotely actuable disconnect assembly comprising first and secondlinearly interregistrable connectors, a pair of backing flangesconnected to said first connector and substantially normally outstandingtherefrom toward said second connector, said second connector having athreaded end portion and an annular shoulder about the mid sectionthereof, a body member having a large centrally located passagewayextending therethrough and terminating at one surface in a passage ofreduced diameter constituting an inwardly extending flange, saidthreaded portion of said second connector extending through saidpassageway to the extent that said flanges are substantially injuxtaposition, a potting assembly threadably engaged upon said threadsextending through said passageway, the walls of said passageway beingformed with a plurality of annular spiral camming grooves, a pluralityof cam stubs registrable with said camming grooves extending outwardlyfrom the periphery of said first connector, said body member containingtwo pairs of interconnecting shafts inwardly extending from non-parallelsurfaces thereof, an explosive squib sealingly, threadably engagedWithin a first shaft of each pair, and a piston member sealingly,slidably journaled within the second shaft of eachof said pair ofshafts, the outer end of each of said pistons contacting said backingflanges, respectively, whereby upon initiation of said squibs, theexpanding gases therefrom slide said pistons outwardly and against saidbacking flanges, thus effecting a rotation of said body memher and a camoperated disconnection of said first and second connectors.

References Cited in the file of this patent UNITED STATES PATENTS

